fs/9p/vfs_super.c

   1 /*
   2  *  linux/fs/9p/vfs_super.c
   3  *
   4  * This file contians superblock ops for 9P2000. It is intended that
   5  * you mount this file system on directories.
   6  *
   7  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   8  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License version 2
  12  *  as published by the Free Software Foundation.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to:
  21  *  Free Software Foundation
  22  *  51 Franklin Street, Fifth Floor
  23  *  Boston, MA  02111-1301  USA
  24  *
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/fs.h>
  31 #include <linux/file.h>
  32 #include <linux/stat.h>
  33 #include <linux/string.h>
  34 #include <linux/inet.h>
  35 #include <linux/pagemap.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/mount.h>
  38 #include <linux/idr.h>
  39 #include <linux/sched.h>
  40 #include <linux/slab.h>
  41 #include <linux/statfs.h>
  42 #include <net/9p/9p.h>
  43 #include <net/9p/client.h>
  44
  45 #include "v9fs.h"
  46 #include "v9fs_vfs.h"
  47 #include "fid.h"
  48
  49 static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl;
  50
  51 /**
  52  * v9fs_set_super - set the superblock
  53  * @s: super block
  54  * @data: file system specific data
  55  *
  56  */
  57
  58 static int v9fs_set_super(struct super_block *s, void *data)
  59 {
  60         s->s_fs_info = data;
  61         return set_anon_super(s, data);
  62 }
  63
  64 /**
  65  * v9fs_fill_super - populate superblock with info
  66  * @sb: superblock
  67  * @v9ses: session information
  68  * @flags: flags propagated from v9fs_get_sb()
  69  *
  70  */
  71
  72 static void
  73 v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses,
  74                 int flags, void *data)
  75 {
  76         sb->s_maxbytes = MAX_LFS_FILESIZE;
  77         sb->s_blocksize_bits = fls(v9ses->maxdata - 1);
  78         sb->s_blocksize = 1 << sb->s_blocksize_bits;
  79         sb->s_magic = V9FS_MAGIC;
  80         if (v9fs_proto_dotl(v9ses))
  81                 sb->s_op = &v9fs_super_ops_dotl;
  82         else
  83                 sb->s_op = &v9fs_super_ops;
  84         sb->s_bdi = &v9ses->bdi;
  85
  86         sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC |
  87             MS_NOATIME;
  88
  89         save_mount_options(sb, data);
  90 }
  91
  92 /**
  93  * v9fs_get_sb - mount a superblock
  94  * @fs_type: file system type
  95  * @flags: mount flags
  96  * @dev_name: device name that was mounted
  97  * @data: mount options
  98  * @mnt: mountpoint record to be instantiated
  99  *
 100  */
 101
 102 static int v9fs_get_sb(struct file_system_type *fs_type, int flags,
 103                        const char *dev_name, void *data,
 104                        struct vfsmount *mnt)
 105 {
 106         struct super_block *sb = NULL;
 107         struct inode *inode = NULL;
 108         struct dentry *root = NULL;
 109         struct v9fs_session_info *v9ses = NULL;
 110         struct p9_wstat *st = NULL;
 111         int mode = S_IRWXUGO | S_ISVTX;
 112         struct p9_fid *fid;
 113         int retval = 0;
 114
 115         P9_DPRINTK(P9_DEBUG_VFS, " \n");
 116
 117         v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL);
 118         if (!v9ses)
 119                 return -ENOMEM;
 120
 121         fid = v9fs_session_init(v9ses, dev_name, data);
 122         if (IS_ERR(fid)) {
 123                 retval = PTR_ERR(fid);
 124                 goto close_session;
 125         }
 126
 127         st = p9_client_stat(fid);
 128         if (IS_ERR(st)) {
 129                 retval = PTR_ERR(st);
 130                 goto clunk_fid;
 131         }
 132
 133         sb = sget(fs_type, NULL, v9fs_set_super, v9ses);
 134         if (IS_ERR(sb)) {
 135                 retval = PTR_ERR(sb);
 136                 goto free_stat;
 137         }
 138         v9fs_fill_super(sb, v9ses, flags, data);
 139
 140         inode = v9fs_get_inode(sb, S_IFDIR | mode);
 141         if (IS_ERR(inode)) {
 142                 retval = PTR_ERR(inode);
 143                 goto release_sb;
 144         }
 145
 146         root = d_alloc_root(inode);
 147         if (!root) {
 148                 iput(inode);
 149                 retval = -ENOMEM;
 150                 goto release_sb;
 151         }
 152
 153         sb->s_root = root;
 154         root->d_inode->i_ino = v9fs_qid2ino(&st->qid);
 155
 156         v9fs_stat2inode(st, root->d_inode, sb);
 157
 158         v9fs_fid_add(root, fid);
 159         p9stat_free(st);
 160         kfree(st);
 161
 162 P9_DPRINTK(P9_DEBUG_VFS, " simple set mount, return 0\n");
 163         simple_set_mnt(mnt, sb);
 164         return 0;
 165
 166 free_stat:
 167         p9stat_free(st);
 168         kfree(st);
 169
 170 clunk_fid:
 171         p9_client_clunk(fid);
 172
 173 close_session:
 174         v9fs_session_close(v9ses);
 175         kfree(v9ses);
 176         return retval;
 177
 178 release_sb:
 179         p9stat_free(st);
 180         kfree(st);
 181         deactivate_locked_super(sb);
 182         return retval;
 183 }
 184
 185 /**
 186  * v9fs_kill_super - Kill Superblock
 187  * @s: superblock
 188  *
 189  */
 190
 191 static void v9fs_kill_super(struct super_block *s)
 192 {
 193         struct v9fs_session_info *v9ses = s->s_fs_info;
 194
 195         P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
 196
 197         if (s->s_root)
 198                 v9fs_dentry_release(s->s_root); /* clunk root */
 199
 200         kill_anon_super(s);
 201
 202         v9fs_session_cancel(v9ses);
 203         v9fs_session_close(v9ses);
 204         kfree(v9ses);
 205         s->s_fs_info = NULL;
 206         P9_DPRINTK(P9_DEBUG_VFS, "exiting kill_super\n");
 207 }
 208
 209 static void
 210 v9fs_umount_begin(struct super_block *sb)
 211 {
 212         struct v9fs_session_info *v9ses;
 213
 214         v9ses = sb->s_fs_info;
 215         v9fs_session_begin_cancel(v9ses);
 216 }
 217
 218 static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf)
 219 {
 220         struct v9fs_session_info *v9ses;
 221         struct p9_fid *fid;
 222         struct p9_rstatfs rs;
 223         int res;
 224
 225         fid = v9fs_fid_lookup(dentry);
 226         if (IS_ERR(fid)) {
 227                 res = PTR_ERR(fid);
 228                 goto done;
 229         }
 230
 231         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 232         if (v9fs_proto_dotl(v9ses)) {
 233                 res = p9_client_statfs(fid, &rs);
 234                 if (res == 0) {
 235                         buf->f_type = rs.type;
 236                         buf->f_bsize = rs.bsize;
 237                         buf->f_blocks = rs.blocks;
 238                         buf->f_bfree = rs.bfree;
 239                         buf->f_bavail = rs.bavail;
 240                         buf->f_files = rs.files;
 241                         buf->f_ffree = rs.ffree;
 242                         buf->f_fsid.val[0] = rs.fsid & 0xFFFFFFFFUL;
 243                         buf->f_fsid.val[1] = (rs.fsid >> 32) & 0xFFFFFFFFUL;
 244                         buf->f_namelen = rs.namelen;
 245                 }
 246                 if (res != -ENOSYS)
 247                         goto done;
 248         }
 249         res = simple_statfs(dentry, buf);
 250 done:
 251         return res;
 252 }
 253
 254 static const struct super_operations v9fs_super_ops = {
 255 #ifdef CONFIG_9P_FSCACHE
 256         .alloc_inode = v9fs_alloc_inode,
 257         .destroy_inode = v9fs_destroy_inode,
 258 #endif
 259         .statfs = simple_statfs,
 260         .evict_inode = v9fs_evict_inode,
 261         .show_options = generic_show_options,
 262         .umount_begin = v9fs_umount_begin,
 263 };
 264
 265 static const struct super_operations v9fs_super_ops_dotl = {
 266 #ifdef CONFIG_9P_FSCACHE
 267         .alloc_inode = v9fs_alloc_inode,
 268         .destroy_inode = v9fs_destroy_inode,
 269 #endif
 270         .statfs = v9fs_statfs,
 271         .evict_inode = v9fs_evict_inode,
 272         .show_options = generic_show_options,
 273         .umount_begin = v9fs_umount_begin,
 274 };
 275
 276 struct file_system_type v9fs_fs_type = {
 277         .name = "9p",
 278         .get_sb = v9fs_get_sb,
 279         .kill_sb = v9fs_kill_super,
 280         .owner = THIS_MODULE,
 281 };